Thermal relay



Aug. 7, 1934. G OAKLEY 1,969,319

THERMAL RELAY Original Filed April 23, 1931 George E. Oa/r/ey $51 14 Gwen mg Patented Aug- 1. 1 1 1,969,319

-- UNITED STATES PATIENT" OFFICE THERMAL RELAY George E. Oakley, Albany, N. Y., assignor to Consolidated Car Heating Company, Inc.,' Albany,

N. Y. a corporation of New York Application April23, 1931, Serial No. 532,340 7 Renewed January 20, 1934 v v s 8 Claims. (01. 175-320) v For a detailed description of the presentform close a circuit to ground. This circuit, which of my invention, reference may be had to the passes through tongue A will short-circuit mag; follow-ingspecification and to the accompanying net E and cause it to drop its armature. Ob drawingiforming a partthereof. viously, as the temperature changes in the vi- In'said drawing Figure 1 is a diagrammatic cinityof the thermostat C, the circuit will be 60 view illustrating one arrangement ofa thermal correspondingly opened and closed and the relay constructed in accordance with the invenheater B will also be alternately cut out and in, tion. Figures 2 to5 both inclusive are. similar but as long as the circuit is closed through the views respectively, illustrating various modificathermostat C, the heat in the vicinity of tongue 10 tions. 1 A will hold said tongue in circuit closed position, 65'

My invention relates to the use of a thermostat so as to maintain short-circuit around magnet to control electrical apparatus. E. When, however, thetemperature falls at C,

It is shown in the five diagrammatic figures and the circuit breaks at that point, the heat on the drawing. will be cut off from the thermal relay B, tongue '15 i Heretofore numberless devices have been in- A will ,drop and remove the short circuit from 30, vented and" patented to enable a thermostat to E. Therefore E will again pick up its armature. safely close the circuit of an electromagnet of In the described operation the contacts of the adequate power to close a circuit, or perform thermostat C will be called on to break only some operation such as the openingor closing the smallnon-inductive current through heater of a damper. My present invention eliminates B. This it can readily do without causing an 15 the need for such devices. It consists in atherare at its, contacts. The tongue A is only remal relay in which there is no self induction qu ed o ea the shunting Circuit around E and consequently no arc'at' the breaking-ofits includingfonly the non-inductive resistance D. circuit. By. 'my invention a thermostat. can Hence the thermal relay as well as the dominate safe1y cl nd; p t t; i s large ing thermostat act without an arc at their con- 80 a circuit .as may be desired for the working of tacts. It will be observed that the heater circuit a-damper, the controlof a pump, the control of is in the form of a branch circuit including the a circuit, or other 'work which it is desired to heater B and thermostat C. Also, that it is perform under thermostatic domination. connected to the first mentioned branch circuit Referring to the drawing C represents a therat a position between the resistance D and the 85 mostat of the mercury type adapted to close or contact A, so .thatthe circuitthrough the heater open an. electric circuit according to. the temshunts said contact A. perature. A- represents thecontactelement of a In the remainingfigures of the drawing the thermal relay consisting: of a bimetallic strip essential operation is the same as that described enclosed by an-eletcriche'aterB. E represents above. In Fig. 2 the non-inductive resistance 90 the electromagnet to be controlled and D is a D .is included in the short circuit around E, but non inductive resistance in series with E. is of such low value't'hatit does not nullify the Normally the relay stands open as shown in short-circuit" effect on E. In Fig. 3 the said the drawing, and only when heat is applied to short circuit includes, instead of the resistance 40 it does its bimetallic tongue A warp up to close D a portion B of the heater B. This allows 95 the circuit, and when heat is abstracted from the short circuit to add to the heating effect of it the tongue A warps down to open the cirheater B which is the position-retaining factor cuit. In brief it is a heat-operated, or thermoon the tongue A. In Fig. 4 the thermostat cirstatic relay. cuit includes, instead of resistance D, a special In Fig. 1 we may assume that the dominated resistance D which is in parallel with resistance 100 magnet E stands with its circuit normally D and is a determinal part of a resistance which closed, from trolley T to non-inductive resistincludes D and D In Fig. 5 the magnet E ance D to magnet E to ground. Then when the acts to close a separate circuit H which passes I temperature at thermostat C reaches a certain through the controlled heaters to ground, outhigh point, it will close a branch circuit through side ,of resistance D, while a special resistance 10 D, non-inductive heater coil B to ground. The D is also included in the circuit of thermocurrent then passing from the trolley T to stat C. Moreover, the magnet E is normally ground through the thermostat C, will energize short-circuited through tongue A which is H the heater B, so that the rise in temperature raised by the thermal rheostat to break and -wil1 quickly cause tongue A to warp up and depressed to close the said short circuit. In ad- 11 dition, the heater-relay coil B has a separate ground of its own instead of being in series with thermostat C as in the other circuits. In this case the thermostat C controls heater B, with which it is parallel, by closing or opening a short circuit around it. These several arrangements are merely illustrative of the various ways in which my thermal relay may be utilized.

What I claim as new and desire to secure by Letters Patent is:

1. In a thermal relay, a circuit including an electro-magnetic relay, a branch circuit connected with the first mentioned circuit at a position to short circuit said relay, said branch circuit including a controlling contact member constructed and arranged to move in response to temperature changes, so as to open or close the branch circuit in accordance with variations of temperature in its vicinity, a heater circuit connected with the branch circuit at a position to shunt the temperature responsive contact, said heater circuit including a heater positioned in the vicinity of said contact, and a determinating thermostat controlling the heater circuit.

2. In a. thermal relay, a magnet, a relay circuit shunting said magnet and including a thermal relay provided with a temperature responsive contact member, a heater located adjacent said thermal relay, a determinating thermostat, and circuit means connecting said heater and said determinating circuit in series and so connected with the relay circuit as to shunt said temperature responsive contact member.

3. A thermal control system comprising a magnet, a relay circuit shunting said magnet and including a thermal relay providedwith a temperature responsive contact member, a noninductive resistance, a heater located adjacent said thermal relay, a determinating thermostat, and circuit means connecting said resistance, said heater and said determinating thermostat in series and so connected with the relay circuit as to shunt said temperature responsive contact.

4. A thermal control system comprising a magnet, a relay circuit shunting said magnet and including a thermal relay provided with a temperature responsive contact member, a noninductive resistance, a heater located adjacent said thermal relay, a determinating thermostat, circuit means connecting said resistance, said heater and said determinating thermostat in series and so connected with the relay circuit as to shunt said temperature responsive contact, and a second non-inductive resistance in the thermal relay circuit.

5. A thermal control system comprising a magnet, a relay circuit shunting said magnet and including a thermal relay provided with a temperature responsive contact member, a noninductive resistance, a heater located adjacent said thermal relay, a determinating thermostat, circuit means connecting said resistance, said heater and said determinating thermostat in series and so connected with the relay circuit as to shunt said temperature responsive contact, and a second non-inductive resistance in the thermal relay circuit and in parallel with the first mentioned resistance.

6. A thermal controlling circuit comprising a thermal switch provided with a temperature responsive member, an electric heater in the vicinity of said switch member, a determinating thermostat, a heater circuit independent of the thermally responsive member but including the heater and said determinating thermostat in series, a branch relay circuit connected with the heater circuit, and another branch circuit including said temperature responsive member, said last mentioned circuit being connected with the heater circuit at a position between the heater and the branch relay circuit.

7. A thermal controlling circuit comprising a thermal switch provided with a temperature responsive member, an electric heater in the vicinity of said switch, a determinatmg thermostat, a non-inductive resistance, a. heater circuit independent of the temperature responsive member but including said resistance, said heat-- or and said determinating thermostat in series, a branch relay connected with the heater circult, and another branch circuit inchidirg said temperature responsive member, said last men-- tioned circuit being connected with the heater circuit at a position between the heater and the branch relay circuit.

8. A thermal controlling circuit comprising a thermal switch provided with a temperatine responsive member, an electric heater in the vicinity of said switch, a. determinating thermmiat, a. non-inductive resistance, a heater circuit including said resistance, said heater and said thermostat in series, a branch relay circuit connected with the heater circuit between said heater and said resistance, and another brand: circuit including said tanperature respomhe member, said last mentioned circuit being connected with the heater circuit at a position between the heater and said branch relay circuit.

GEORGE E. OAKLEY. 

